code: def test_register(profiler):
      prof = profiler()
      try:
          prof.register()
          get(dsk2, "c")
          n = len(prof.results)
          assert n > 0
          get(dsk2, "c")
          assert len(prof.results) > n
      finally:
          prof.unregister()
  
imports: from __future__ import annotations
  import contextlib
  import os
  import warnings
  from operator import add, mul
  from timeit import default_timer
  import pytest
  from dask.diagnostics import CacheProfiler, Profiler, ResourceProfiler
  from dask.diagnostics.profile_visualize import BOKEH_VERSION
  from dask.threaded import get
  from dask.utils import apply, tmpfile
  from dask.utils_test import slowadd
label_desc: Use image node_id 7 for calling a global function with example usage: test_register(profiler) without return types